Michael,
Home Depot didn't carry it in the Atlanta area so I had to go to Lowes. Make sure you get some GM carpet adhesive, have a good sharp razor knife and the foil tape. This can be hard to find as it was over in the tape and adhesive section rather than with the insulation when I went looking. The beauty of this stuff is that the foil backing on the front and back is somewhat mallable and retains its shape, allowing you to shape it and pull it out for the cuts.
I see you live in Rancho Cambodia, my old stomping grounds. 4 years at Sac State living off La Riviera drive in several rentals before I bought my first house in 85 over in that planned unit development behind Capital City Christian.
Good luck. You won't be disappointed.
Bob